This invention relates to seal welding, that is, to the welding of a tubular member to a plate through which the tubular member extends, by welding around the periphery of the member. More specifically, this invention relates to method of making stream feeders or bushings for flowing streams of heat-softened mineral material, such as glass, and more specifically to a method of producing a stream flow section of tip plate of a feeder.
Endeavors have been made to fabricate a feeder tip section by drilling holes in a plate, inserting flange tubular members in the openings and electric resistance welding the flanges of the eyelet to the plate to form a tip section. The performed members provide a convenient way to make the necessary projections or tips. A method of this character is disclosed in the Leedy and Russell U.S. Pat. No. 2,933,590. In this method, a principal portion of the flange of a tubular member is fused during electric resistance welding. However, because the electrode is in direct contact with the fused metal of the member, there is a tendency for the member to become contaminated with metal of the electrode. Also, the heat generated may tend to warp or distort the performed tubular member or tip, and thereby change the size of the member passageway.
The use of preformed tubular members in feeder fabrication is desired because it has the potential advantages of uniform tips and ease of construction. Electron beam welding has been used to attach preformed tubular members to an orificed plate in a discontinuous tip by tip welding operation. Welding one tubular member at a time in a discontinuous operation has proven to be a slow and costly way of manufacturing feeder tip sections.
An improved method of manufacturing a stream feeder is desired.